Exertional Cardiac and Pulmonary Vascular Hemodynamics in Patients With Heart Failure With Reduced Ejection Fraction

Background: Exertional dyspnea is a cardinal manifestation of heart failure with reduced ejection fraction (HFrEF), but quantitative data regarding exertional hemodynamics are lacking.

Objectives: We sought to characterize exertional cardiopulmonary hemodynamics in patients with HFrEF.

Methods: We studied 35 patients with HFrEF (59 ± 12 years old, 30 males) who completed invasive cardiopulmonary exercise testing. Data were collected at rest, at submaximal exercise and at peak effort on upright cycle ergometry. Cardiovascular and pulmonary vascular hemodynamics were recorded. Fick cardiac output (Qc) was determined. Hemodynamic predictors of peak oxygen uptake (VO₂) were identified.

Results: Left ventricular ejection fraction and cardiac index were 23% ± 8% and 2.9 ± 1.1 L/min/m², respectively. Peak VO₂ was 11.8 ± 3.3 mL/kg/min, and the ventilatory efficiency slope was 53 ± 13. Right atrial pressure increased from rest to peak exercise (4 ± 5 vs 7 ± 6 mmHg,). Mean pulmonary arterial pressure increased from rest to peak exercise (27 ± 13 vs 38 ± 14 mmHg). Pulmonary artery pulsatility index increased from rest to peak exercise, while pulmonary arterial capacitance and pulmonary vascular resistance declined.

Conclusions: Patients with HFrEF suffer from marked increases in filling pressures during exercise. These findings provide new insight into cardiopulmonary abnormalities contributing to impairments in exercise capacity in this population.

Clinical trial registration: clinicaltrials.gov identifier: NCT03078972.